stdenv: implement crossOverlays

crossOverlays only apply to the packages being built, not the build
packages. It is useful when you don’t care what is used to build your
packages, just what is being built. The idea relies heavily on the
cross compiling infrastructure. Using this implies that we need to
create a cross stdenv.

1 files changed, 2 insertions, 2 deletions

diff --git a/pkgs/stdenv/darwin/default.nix b/pkgs/stdenv/darwin/default.nix
index 5fb410b64ebdc..b7d8e3ba5236b 100644
--- a/pkgs/stdenv/darwin/default.nix
+++ b/pkgs/stdenv/darwin/default.nix
@@ -1,5 +1,5 @@
 { lib
-, localSystem, crossSystem, config, overlays
+, localSystem, crossSystem, config, overlays, crossOverlays ? []
 
 # Allow passing in bootstrap files directly so we can test the stdenv bootstrap process when changing the bootstrap tools
 , bootstrapFiles ? let
@@ -16,7 +16,7 @@
   }
 }:
 
-assert crossSystem == null;
+assert crossSystem == localSystem;
 
 let
   inherit (localSystem) system platform;